LukaKordic

class WeatherRepositoryImpl(private val weatherApi: WeatherApi,
                            private val weatherDao: WeatherDao) : BaseRepository<WeatherInfo, WeatherEntity>(), WeatherRepository {
  override suspend fun getWeatherForLocation(location: String): Result<WeatherInfo> {
    return fetchData(
      apiDataProvider = {
        weatherApi.getWeatherForLocation(location).getData(
          fetchFromCacheAction = { weatherDao.getWeatherInfoForCity(location) },
          cacheAction = { weatherDao.saveWeatherInfo(it) })
      },
      dbDataProvider = { weatherDao.getWeatherInfoForCity(location) }

LukaKordic

interface WeatherApi {
  
  @GET("weather")
  suspend fun getWeatherForLocation(@Query("q") location: String, @Query("appid") apiKey: String = API_KEY): Response<WeatherInfoResponse>
}

LukaKordic

@Dao
interface WeatherDao {
  
  @Transaction
  suspend fun updateWeatherAndReturn(weather: WeatherEntity): WeatherEntity {
    saveWeatherInfo(weather)
    return getWeatherInfoForCity(weather.name ?: "")
  }
  
  @Insert(onConflict = OnConflictStrategy.REPLACE)

LukaKordic

sealed class Result<out T : Any>
data class Success<out T : Any>(val data: T) : Result<T>()
data class Failure(val httpError: HttpError) : Result<Nothing>()

class HttpError(val throwable: Throwable, val errorCode: Int = 0)

inline fun <T : Any> Result<T>.onSuccess(action: (T) -> Unit): Result<T> {
  if (this is Success) action(data)
  return this
}

LukaKordic

class GetWeatherUseCaseImpl(private val weatherRepository: WeatherRepository) : GetWeatherUseCase {
  
  override suspend operator fun invoke(location: String) = weatherRepository.getWeatherForLocation(location)
}

LukaKordic

interface WeatherApi {
  
  @GET("weather")
  suspend fun getWeatherForLocation(@Query("q") location: String, @Query("appid") apiKey: String = API_KEY): Response<WeatherInfoResponse>
}

LukaKordic

data class WeatherInfoResponse(val id: Int? = 0,
                               val weather: List<Weather>?,
                               val main: MainInfo?,
                               val name: String? = "") : RoomMapper<WeatherEntity> {
  override fun mapToRoomEntity() = WeatherEntity(id ?: 0, weather ?: emptyList(), main ?: MainInfo(), name)
}

data class MainInfo(val temp: Double? = 0.0,
                    val pressure: Double? = 0.0,
                    val humidity: Int? = 0)

LukaKordic

@Entity(tableName = WEATHER_TABLE_NAME)
data class WeatherEntity(@PrimaryKey val id: Int? = 0,
                         val weather: ArrayList<Weather>?,
                         @Embedded
                         val main: MainInfo?,
                         val name: String? = "") : DomainMapper<WeatherInfo> {
  
  override fun mapToDomainModel() = WeatherInfo(main?.temp ?: 0.0, main?.humidity ?: 0, main?.pressure ?: 0.0)
}

LukaKordic

data class WeatherInfo(val temperature: Double, val humidity: Int, val pressure: Double)

LukaKordic

class WeatherViewModel(private val getWeather: GetWeatherUseCase) : BaseViewModel<WeatherInfo, WeatherViewEffects>() {
  
  fun getWeatherForLocation(location: String = DEFAULT_CITY_NAME) = executeUseCase {
        getWeather(location)
            .onSuccess { _viewState.value = Success(it) }
            .onFailure { _viewState.value = Error(it.throwable) }
      }
}